CZ367797A3 - Reinforced structural member - Google Patents

Abstract

A reinforced structural member (18) has a w-shaped reinforcement member (32) that carries a thermally expandable resin based material (36). The w-shaped reinforcement member (32) is placed in the channel (34) of a hollow structural member (20) over a transverse pin (30) which fits through the slot of the reinforcement member (32). The structural member (20) is heated to expand the resin based material (36) which locks the reinforcement member (32) in place, thereby significantly strengthening the structural member.

Description

Technical field

The present invention relates generally to automotive structural members, more specifically to reinforcements for increasing the strength of automotive structural members.

BACKGROUND OF THE INVENTION

Lightweight structural elements, which are characterized by high strength, are necessary in many modifications in many fields, especially in the automotive industry. In the past, many special metal alloys and other processes have been proposed for the manufacture of high-strength structural members, but in many cases the cost of these alloys is too high, including the automotive industry. Thus, there is a need for lightweight and inexpensive reinforced structural members that could currently improve the construction of structures.

· # ·

A number of patents have been involved in the construction of motor vehicle components. US Patent No. 4,901,500 entitled Light Combination Beam deals with a reinforced car door girder. It comprises an open channel-like metal member with a longitudinal depression filled with a thermosetting or thermoformable resin-based mass. U.S. Patent No. 4,900,930 entitled Torsion Bar Production discloses a hollow torsion bar reinforced with a mixture of resin and filler. The tube is cut longitudinally and filled with resin-based material.

U.S. Patent No. 4,751,249, entitled Structural Element Reinforcement Insert and Method of Manufacture and Use, describes a pre-cast structural member reinforcement insert that is formed from a plurality of granules comprising a.

Á Á za fr hot-cured resin and initiator in the structural member. The casting becomes volume and hardens. Also in U.S. Pat.

No. 4,978,562 entitled Combination Spherical Door Beam with a Binding Foam Core in the Central Part of the Tube, a combination door beam with a resin-based filler is described which does not occupy more than a third of the space of the metal tube.

U.S. Patent Application Serial No. 245,798 of May 19, 1994, entitled Combined Laminated Carrier Beam, describes a hollow laminate beam typically characterized by a high coefficient of adhesion, the outer portion of which is separated from the inner tube by a thin layer of structural foam.

Although these prior art reinforcement techniques are advantageous in some fields, it is necessary to substantially reinforce parts of the structure, particularly in the stressed parts, in a manner not only inexpensive but also useful in mass production.

In addition, cyanofuranidine is known to be a commonly used latent hardener of foamed epoxy polymers. The nominal particle size of the most commonly used mass is approximately 80 microns. For greater reactivity, smaller particles are sometimes used. 90% of the particles are less than 30 microns. In the methods used in the past, the foamed polymer may occasionally ignite in the normal use of hardeners, because the heat induced by the exothermic curing reaction is not properly dissipated. However, this solution is not practical if the set temperature in the furnace corresponds to another intent, for example pounding of paint and the like.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a reinforced structural member.

The reinforced structural member has an elongate groove into which reinforcement is inserted. There is a gap in the reinforcement, lower through

passing the tip or other reinforcing means. The tip is attached to opposite side walls of the structural member. The sides of the reinforcement are open and its interior is filled with resin-based material. Installation of the reinforced structural member βθ is done by placing a reinforcement filled with resin-based material on the fixed point. The open sides of the reinforcement with the mass inside are adjacent to the side walls of the structural member, with the tip passing through the free reinforcement gap. The structural member, which may be part of the frame of a motor vehicle, passes through a furnace in which the resin-based mass increases its volume and thereby firmly adheres to the interior of the side walls of the structural member. By increasing the volume of the resin-based mass, the reinforcement, the granulated mass and the structural member are joined into one integral part.

It is a further object of the present invention to provide openings in the reinforcement adjacent the bottom of the structural member and which allow the resin to flow through the openings, adhere to an additional portion of the surface of the structural member and thereby bond it more firmly to the reinforcement.

It is a further object of the present invention to provide a novel epoxy-based reinforcing composition comprising an epoxy resin, an elastomer, a filler, diatomaceous earth, high strength glass particles, together with a hardener, catalyst and initiator.

The present invention greatly increases overall strength

constructional article a decreases so the number cracks in stressed v which is structural article umÍBtěn.

Brief Overview of pictures

Fig. 1 is an overall view of a portion of a padded member reinforced according to the present invention.

M * · Fr ·· ····;] ,. • 9 * · · * > » • V • * * i ♦ • · · * • « • · «♦ • • ♦ • • · · • · · 4 • · •

Fig. 2 is a side view of the beam member of Fig. 1, the cell is partially exposed to show the location of the reinforcement and the transverse tip.

Fig. 3 is an overall view of the filler carrier prior to insertion into the empty structural member of Figs. 1 and 2.

Figure 4 is a cross-sectional view of the carrier of Figure 3 taken along lines 4-4.

Figure 5 is an overall view of an empty transverse member before inserting reinforcement.

Figure 6 is a side view of a partially exposed beam reinforced according to another embodiment of the present invention.

Figure 7 is a cross-sectional view of the reinforcement of Figure 6 taken along lines 7-7.

Figure 8 is an overall view of the carrier of Figure 3 without resin-based padding.

Figure 9 is a side view of a reinforcement in another embodiment of the present invention.

Figure 10 is a side view of the reinforcement and spike in another embodiment of the present invention.

Fig. 11 shows the projected form of the beam member of Fig. 1 with the filler removed.

Figure 12 is a side view of a reinforcement in another embodiment of the present invention.

with an empty component 20 and a wolf, or

Figure 1 shows a reinforced structure 18

with a sealing label 22 (indicated). The structural member 20 consists of two opposing side walls 24/24 and thus the plane of the bottom 22 / has a trough shape. Opposite side tents 24 and 26 are connected by a tip 30 (best seen in Figure 5). The tip 30 serves as a shock absorber and for clamping the reinforcement

32. The reinforcement 32 is inserted into the elongate groove or cavity 34 of the empty structural member 22 and includes a support 33 (preferably shown in FIG. 8) into which the reinforcing / bonding mass 32 is inserted. to better illustrate the position of the reinforcement 35 and the tip 32

The empty structural member is preferably made of metal, e.g.

made of steel, and is preferably part of the construction of a motor vehicle. The reinforced structural member 18 finds the subsequent most preferred applications in automotive sheeting and / or beam treatment.

The support 33 (see FIGS. 3, 4, 8) consists of outer walls 32 and 42 (inner walls 42 and 44), lower walls 4fi and 42 and a connecting wall 52 which forms a pair.

The groove-shaped cavities and / or reservoirs 52 and 54. The assembly (as best shown in Figures 4 and 8) then forms a cavity 56 in the C-shape into which the resin is inserted.

The resin-based reinforcing / bonding mass 36 thus forms a C-shaped filler or core 58.

A variety of forms are applicable to the carrier 33 due to its use. The W-shaped arrangement, however preferred, is only one of these forms. For example, the carrier 33 may have a corrugated form 70 or an inverted U-22 shape (where the filler is positioned externally, i.e. the carrier structure has no outer walls).

It is also possible to completely eliminate the carrier 33 and to use the molded fill mass Z4 itself, as shown in FIG.

12. In principle, it is sufficient that the reinforcement 32 is provided with means for receiving and retaining the resin-based filler and means for fastening at a certain location by means of a clamping element such as a spike 35. · Most preferably · · I i ί ί ί ί ί ί ί ί a a a a a a a a a a a a a a a and

6, the support 33 will define one or more spaces for retaining the reinforcing / binding mass, and these or these spaces will be open on the sides so that the reinforcing / binding mass can be spilled laterally and joined ηθ by the side walls 24 and 26 of the hollow structural member 2ΏColor caliber 33 can vary, but is usually between .025 and approximately .060. The dimensions of the reinforcement 32 should be close to that of the groove 34 so that there are at least some contact points between the support 33 and the side walls 24 and 26, but these dimensions should not be such that the groove walls are stretched when the reinforcement is inserted. The tip 30 is preferably of metal and serves, as mentioned, to firmly clamp the reinforcement 32 through the gap 60 of the support 33 defined by the inner walls 42 and 44 and the connecting wall 50 of the support 33. The reinforcement / binder mass 36 will be fully described as well as the assembly method of the reinforced structural member 18 below.

Another aspect of the invention is illustrated in the figures

V- ¹ T

6 and 7, on which there is a reinforcement 32 with a plurality of holes or channels 42 through which the mass 36 flows during assembly. This creates additional joints 64 on the plane of the bottom 28 of the hollow member 20. By providing similar holes 62, the reinforcement and reinforcement strength of the reinforced member 18 is reinforced and reinforced. All other features of the reinforced member 18 are identical to the features described in FIG. -5.

A variety of materials can be used in the manufacture of the resin-based reinforcing / binding compositions 36. The dose of such a suitable substance should be such that it does not leak much before curing or after partial curing after the carrier 33 has been filled prior to its insertion in the groove 34. It would therefore be preferable for the carrier 33 to be filled preferably with reinforcing / binder. In addition, a sufficient amount of reinforcing / bonding mass 36 is also important to constantly press against the sidewalls 24 and 26 and against the plane of the base 2fi (see FIGS. 6 and 7), thereby exerting the desired internal pressure. It is also important that the reinforcing / bonding mass 36 holds firmly on the inner surface of the support 33 the same as on the inner surface of the sidewalls 24 and 26. The reinforcing bonding mass 36 must also be sufficiently heat resistant to withstand the temperatures of baking colors in the furnace and the like. The reinforcing / bonding mass 36 should also be lightweight and inexpensive and, in short, should impart excellent mechanical properties to the reinforced structural member ifi.

More precisely, the density of the reinforcing / bonding composition 36 should be between 0.5 and 1 gram per cubic centimeter before fully curing and after fully increasing its volume in the carrier space between 0.4 and 0.7 grams per cubic centimeter. The filler 58 should have an internal pressure of at least 70.3 kilograms per square centimeter and more preferably about 105.5 kilograms per square centimeter or more after it has increased in volume and after the internal pressure has grown. The bonding force between the filler 58 and the steel sidewalls 24 and 26 should be high enough to maintain bonding between the two materials. This minimizes the possibility of separating the filler 58 from the sidewalls 24 and 21fi as well as the carrier 22. The cured filler 58 should withstand short-term temperatures above 231 ° C without exposure to other adverse circumstances and longer term temperatures of up to 79 ° C. deformations caused by heat.

The filler Sfi may be introduced directly into the support 23 by closing its open side walls 38 and 40 and injecting or pouring a liquid or paste mass therein. Here, the mass 2fi can be solidified by curing or cooling. Alternatively, the filler 58 will be formed in advance and only then inserted into the space 56 of the carrier 33.

• · «· ·

The resin-based reinforcing / binder mass 35 preferably consists of a synthetic resin, an expandable self-foaming agent and a filler. All percentages are by weight unless otherwise stated. In one embodiment, the proportion of synthetic resin is from about 45 to about 70 percent of the weight of the filler 52, preferably from about 50 to about 60 percent. The porous structure is most desirable because it is characterized by low density, high strength and, in addition, low weight. The self-foaming agent may comprise an initiator, e.g. azodicarbonamide or β, β-oxybis (benzenesulfonyl hydrazide) having a weight fraction of about 0.1 až to about 10,, preferably about 0.5 až to about 2 hmotnosti of the filler weight 58. In addition, in some applications, it is preferable to use plastic thermosetting or thermoformable microparticles which retain their smaller volume until the reinforced structural member is exposed to an elevated temperature at which the mass 36 increases in volume. It will be appreciated that the mass 35 will only increase in volume after the reinforcement 32 has been inserted into the groove 34. Where initiators are used as a self-expanding agent, their weight fraction is about 0 »to about 10» and more preferably about 1.5 »to about 3. Filling Weights 52. Suitable fillers include a variety of glass fillers or glass fillers. -! t plastic microparticles, kieselguhr, calcium carbonate, ground and crushed glass fibers. The weight fraction of the filler in the weight of the filler 59 varies from about 20 to about 50, preferably from about 25 to about 40.

Synthetic resins useful in the present invention preferably include thermosetting resins such as mono-component epoxy resins, vinyl ester resins, thermosetting polyester resins and urethane resins. The average molecular weight of the resin component ranges from about 1,000 to about 5,000,000. When a thermosetting resin is used in the mass 36, various catalysts such as treated urea and borontrichloride are also included. To cure the resin is. a curing agent such as dicyandiamide is used. The functional amount of the catalyst typically ranges from about 0.1 * to about 5 * relative to the weight of the resin with a corresponding loss in one of three components: resin, self-foaming agent or filler. Some thermoformable resins may also be suitable

Most preferably, the composition of the composition 36, as well as the composition comprising another aspect of the present invention, is an uncured one-component epoxy system in the form of a high viscosity paste embedded in the carrier 33 as mentioned above. Using this preferred one-component epoxy paste, the uncured mass 36 and hence the reinforcement member 32 can be washed, crosslinked, or otherwise treated with an alkaline or acidic solution without appreciable disruption of the mass 36. The mass 36 in this form is thus acid-resistant and remains uncured. Especially in the automotive industry, this procedure allows the application of the reinforcement member 32 at an early stage of the manufacturing process.

Accordingly, in one preferred embodiment, the 36 weight percent epoxy resin comprises from about 30 * to 70 *, elastomers such as polybutyl rubber, acrylonitrile-butadiene rubber (ABR) or polyisoprene from about 0 * to 20 *, a filler such as calcium carbonate, foamy kieselguhr, and glass microparticles of high strength from about 1 * to 30 * and initiators such as azodicarbonamide or β, P'-oxybis (benzenesulfonyl hydrazide) from about 0 * to 10 *.

The composition 36 additionally comprises a curing agent such as dicyandiamide or cyanoguanidine in a weight range of about 2 * to 10 *. It has been found that the particle size of this curing agent is important for the preferred composition of the composition 36. When using a crushed or scattered curing agent whose 40 * particles have a diameter greater than 15 microns and are fully mixed with other constituents of the composition 36, in car paint furnaces, curing is achieved without thermal damage. In other words, the use of a one component epoxy resin with a cyanoguanidine b admixture containing very coarse particles does not incinerate (or even partially) the interior of the cured epoxy foam.

The mass 36 preferably contains from about 0 * to 5 * catalyst such as treated ureas and / or borontrichloride. Black powdered carbon may also be present in the range of about 0 * to 10 *.

In a most preferred embodiment, the mass 36 comprises hydrophobic diatomaceous earth in an amount of from about 1 * to 6 * and from about 18 * to 27 * high strength glass particles with a diameter ranging from about 20 microns to about 400 microns. The high strength particles should have a hardness of at least 500 psi.

The most preferred epoxy resins are solid bisphenol A and solid bisphenol F including a liquid epoxy resin. One of these epoxy resins is sold as DGEBPA resin by The Peninsula Polymer Company,

The most preferred elastomer is acrylonitrile-butadiene rubber sold under the designation NIPOL 1312 by The Zeon Company in Kentucky.

A preferred filler is stearic acid treated calcium carbonate, sold as WINNOFIL SPT by The Reaper Company in Massachusetts.

Preferred kieselguhr is sold as CAB-O-SIL TS 720 by The Cabot Company in Illinois.

Preferred high strength glass particles are sold as B38 Glass Bubbles by The 3M Company in Minnesota.

♦ ·· • ·· • · ··· · «· « ♦ « • · · • · · * · • · · • «· e • • 9 • ♦ · · ♦♦ • 9 99 «

The most preferred hardener, initiator are sold as a curing catalyst

Dicyandimine G by SKW &

I>

and

Georg ·! i, or j as

Pennsy1vania), or

Connecticut).

In the most preferred (uncured) should have

AMICURE

UR (Air Products Company such as CELOGEN OT (Uniroyal Company Finishing) would have a paste-like starting mass 36. The mass 36 can be prepared by conventional methods.

by mixing the ingredients.

Table 1 such as

Weight in Epoxy resin 50.45 acrylonitrile-butadiene rubber 4.33 calcium carbonate 5.81 black powdered carbon 0.13 kieselguhr 3.55 high strength glass particles 22.40 hardener 4.33 catalyst 1.29 initiator 0, 71

The following table shows the preferred compositions for the resin-based reinforcement / binder mass 36. This table is to be understood as a preferred composition only, in another application a different composition may be appropriate.

Mounting of the reinforced component Ϊ8 se (see Fig.

and 3) is carried out in such a way that the reinforcing / binding mass 3fi prepared by the resin is inserted into the carrier 33 as described above. At the same time, a variety of filled reinforcements 32 can be prepared and stored for future use. It is to be understood that when the reinforcement member 32 is to be inserted into the groove 34, the reinforcement / binder mass 36 has such a high viscosity that it holds within the reinforcement member 32 but is still able to increase its volume, fully mature or solidify as a carrier 58 in the form of a carrier 33 in the groove 34- Holes are drilled in the side walls 24 and 26 and the tip 30 passes through them. The tip 30 is intended to hold the reinforcement member in the groove 34 securely. for example, roughening of the inner surface of the opposing walls 24 and 26 The tip 30 is preferably tightly welded so that it passes through the channel 34 (best shown in Figure 5) and provides support for the article 18.

The reinforcement 32 is inserted into the groove 34 in such a way that the tip 30 passes through the gap 60 and thereby firmly holds the reinforcement 32 in place (i.e., prevents the reinforcement 32 from longitudinally moving within the groove 34). is then applied to the cavity of the structural member 26 and welded tightly so that the trough 34 is completely closed. As the vehicle passes through the paint furnace, the reinforcing / bonding mass 36 gains heat in volume, thereby providing a rigid filler 58 that seals the reinforcement 32 in the groove 34 as mentioned. In other words, after increasing the B volume, full solidification or curing, the reinforcement 32, the filler 58 and the opposing walls 24 and 26 form a single unit which imparts considerable strength to the reinforced structural member 18. Although the time and temperatures may vary greatly depending on the choice of the mass 36 mentioned, exposed to a sufficiently high temperature depending on the amount of catalyst, curing agent and its own amount.

the substances used to form, if preferred, in the preceding tables

The lining mass had 36

The reinforced structure 18 has a number of advantages over structures previously used in the art. By sophisticated placement of the reinforcement 32 at pressurized locations, metal fatigue and cracks can be reduced without the use of better metals to produce the structural member 20. Thus, the carrier 33 preferably occupies less than half of the cone 20 (and hence the groove). If the carrier 33 is a series (three preferably in the form of columnar formations) or which are interposed between lateral pressures as in W-shaped form by several U-shaped formations, walls 24 and 26. The resistance to longitudinal axis passing through walls 24 and 26 and hence along the length of the groove is considerable.

It would be desirable for the carrier 33 to function as a container for the filler 58 which prevents deformation, splitting, cracking and spontaneous movement of the filler. This is particularly important where the filler 58 is a load carrying unit. The filler 58, on the other hand, stabilizes the carrier 33 so that it does not move when the load is not consumed.

The description and preference of a particular aspect of the invention on these pages should not be construed as limiting the invention, since many modifications can be made by the person skilled in the art as a result of this description. All modifications that are within the spirit and scope of the invention are considered to be part of the invention.

Claims (22)

Patent claims 1. Reinforced structural member, comprising: a structural element with a defined interior space; a reinforcement inserted therein, comprising a carrier and a thermally increased volume filler, characterized in that the carrier serves as a housing of the filler and that the filler is firmly connected to the structural member and the carrier; means for fastening the reinforcement in the structural member. The invention as defined in claim 1, characterized in that there is at least one opening in the carrier through which a portion of the thermally increased fill volume escapes, the filler being firmly connected to the structural member by this excess portion. 3. The invention as defined in claim 1, characterized in that a gap is defined in the carrier and in that a portion of said fastening means is connected to the structural member and extends through said space, at least partially through said gap, thereby fastening the reinforcement in said space. . 4. The invention as defined in claim 1, wherein the thermally expanded mass is resin-based. The invention as defined in claim 1, characterized in that the structural member is part of a metal frame, in that the shape of the carrier defines a gap and at least one space thereby. That the thermally expanded mass is a resin-based mass embedded in the space by passing a portion of the fastening means through and associated with the structural member space, and by the portion of the fastening means passing through the carrier gap securing the structural member within the space . 0 · • 0 0 0 • 0 0 ♦ 0 Φ000 0 0 0 « 6. The invention as defined in claim 5, characterized in that. • 0000 • 0 0 0 0 • 0 That the carrier is a W-shaped metal strip delimiting two spaces, one of these spaces is adjacent to one side i 4 * ·. said space, the second space wherein the mass, with the thermally enlarged to the other side of the space, constitutes the volume of both these spaces. The invention as defined in claim 5, wherein the W-shaped metal strip has a longitudinal axis extending through both said spaces and a transverse axis perpendicular to said longitudinal axis, and wherein said channel gap along the transverse axis, a structural member of the opposite sidewall. and W is disposed in a space with one side wall to the wall a metal strip in the shape of having two letters said transverse axis extending from the other. 8. A reinforced structural member, comprising: a steel beam defining an elongated along the longitudinal axis; a resin holding two opposing side walls of the trough, the elongate trough being a metal reinforcement disposed in the trough, the reinforcement having at least one columnar formation and at least one gap, the axis of the columnar formation extending between opposite side walls and perpendicular to the longitudinal axis; tip B connected by a steel beam passing through the gap; r < a resin-based filler placed in the reinforcement proBtor, the filler being firmly connected to the side wall and the reinforcement. The invention as defined in claim 8, wherein the filler is formed of a thermally expanded resin-based mass. 10. The invention as defined in claim 8, characterized by a columnar form. in that the space defined by the resin holding the metal reinforcement has a W-shaped structure which defines three ·· · * «« 11. A reinforcement insert for reinforcing an empty structural member, comprising: a metal support delimiting the space of the filler and the gap to fit on the tip; the resin-based filler inserted into the filler space, wherein the filler is not fully expanded and not fully cured. 12. The invention as defined in claim 11, wherein the metal carrier is W-shaped. 13. A reinforced structural member comprising: a structural member defining a space; a reinforcement inserted in said space, said reinforcement being unconditionally a resin-based mass having a thermally increased volume firmly connected to said structural member, said mass defining a gap; means for fastening the reinforcement to the structural member including the spike for inserting the gap. 14. The invention as defined in claim 13, wherein the fastening means is a point fixedly connected to the structural member. 15. Reinforcing the structural member with, the following steps: manufacture of a metal support, characterized by a resin deposit and a gap; deposition of the expandable mass on the basis of the resin space into the carrier space; preparing the empty structural member b with a longitudinal groove and attaching the tip to the groove of the empty structural member; inserting the metal carrier filled with the resin-based mass into the groove, wherein the carrier gap abuts the tip; increasing the volume of the resin-based mass so that the carrier is firmly attached to the structural member. ··· Pijj * 16. The invention as defined in claim 15, characterized in that the heat and volume of the resin-based mass is increased by the heating of the structural member. are: 17. Reinforced motor vehicle frame. having an empty portion of the frame b with opposing side walls defining a longitudinal groove; the tip is rigidly connected to one side wall and the other end to the other; a W-shaped metal strip delimiting two spaces and a gap; a thermally expanded resin-based filler rigidly coupled to the W-shaped metal band in both said spaces; a V-shaped metal strip inserted into the empty portion of the frame between its opposed side walls and the side walls firmly intoxicated with resin-based filler; nib located in the gap. řt í 18. The invention as defined in claim 17, wherein the frame has a bottom wall connecting opposing side walls, wherein the Vr-shaped metal strip has at least one opening through which a portion of the heat-increased fill volume escapes, and wherein the portion of the enlarged filler is firmly attached to the bottom Bena. 19. The invention defined in claim 1, wherein the expanded filler comprises an epoxy resin, an elastomer, diatomaceous earth, high strength glass microparticles, an initiator, and a hardener. The invention as defined in claim 19, further comprising a filler and a catalyst. 21. elements: 22. by rubber. Filling composition for reinforcing epoxy resin elasturner kieselguhr glass microparticles by high initiator hardener The invention defined in claim 21, wherein said elastomer is acrylonitrile-butadiene